My father never got to travel the world as I have been able to. He never got to leave the United States or visit the continent of Africa, where his ancestors had come from in chains and in the cargo holds of ships. But he traveled the world plenty, through his mind and through his actions, as a lifelong student, teacher, and activist.

And on one very special night in 1990, world history came to him, when he took me to see Nelson Mandela speak at the Los Angeles Coliseum, after spending 27 years in jail and before leading South Africa as its first black president.

Sharing that night with my father was one of the happiest experiences of my life. I was 12 years old. Throughout my childhood, I had watched my father learn about, organize around, and try to educate people on South Africa and its apartheid government. He helped start a chapter to fight apartheid in Ventura County, Calif. As a high school and community college teacher of U.S. history and "Afro-American" studies, he felt it was important to fight against the injustice the South African people were subjected to, even if they were on the other side of the world.

My father knew something about the demeaning and debasing effects of encountering racial prejudice in many aspects of his life. One of the most humiliating things he survived was the sometimes daily harassment he'd receive while he was in the United States Air Force and was trying to go to college at night on the GI Bill. He had commanding officers who did everything they could to make life for an "uppity Negro" trying to get an education as difficult as possible, up to and including denying him leave from his base when they knew he had an exam. For years, when he drove through the San Fernando Valley, he'd be stopped by the same police officers, removed from his VW Bug, made to put his hands on the hood, and searched. They never found anything. These were cops who knew who my dad was and who actually worked with him at times on his base, where he was a military police officer. But, in his VW, he was black and off duty, and they were white cops on duty, and they knew that they could screw with him, and they did. Repeatedly.

I remember being with my dad once when I was 6 or 7, and watching the suppressed rage and humiliation in his face when he was pulled over on Oxnard Boulevard and searched by cops. He asked them not to do it in front of his son, but there was little he could do in that moment.

There was a lot he could do later, and he did it. I think my dad channeled his frustration into empathy for others going through similar things. He became an activist, and once he attained the station in life of being a public-school teacher, he tried to make the world better not just for his community and his family, but for people he'd probably never meet.

Nelson Mandela was one of my father's living heroes. He was a black man who experienced discrimination in ways far more extreme than my dad did; he was literally imprisoned, but seemed to be spiritually free, and he fought with dignity, grace, and a lack of vengeance. In wanting to support Mandela's attempt to dismantle South Africa's government, which oppressed black people in ways he could relate to, my dad helped raise consciousness about apartheid. He and like-minded people of all races worked in concert at a very grassroots level. The cassette of "Soweto Never Sleeps" was well worn in our house.

All of this was done without Kickstarter, Facebook, Twitter, or YouTube. Before the internet, this meant meeting in person, raising money in person, and creating physical leaflets about the horrors of apartheid. There were newsletters, but without social media (and with virtually no coverage in the mainstream press), these local anti-apartheid groups around the world acted largely in isolation from one another, with virtually no idea if what they were trying to do was having any effect whatsoever.

My earliest memories of activism are getting schlepped at ungodly hours to set up tables at community fairs. I recall more than one Fourth of July or Memorial Day when my family spent part of the day tabling the anti-apartheid booth at a street fair, trying to convince our neighbors that they should care about the plight of black South Africans. It is easy to forget how unpopular and (even "unpatriotic") supporting Mandela in this way was in the 1980s. Ronald Reagan, the wildly popular conservative president, branded Mandela as a communist and vetoed the Comprehensive Anti-Apartheid Act in 1986. Though it was overridden in Congress, the act passed without support from Wyoming Rep. Dick Cheney. (As vice president in 2006, Cheney still maintained that Mandela's African National Congress was a "terrorist" organization and said, "I don't have any problems at all with the vote I cast 20 years ago.'')

I learned from my father that it is important to be concerned about the plight of people even if you can't see them, and that it is important to try to help them, even if your efforts seem futile. He toiled away for years raising smalls sums to of money to support the ANC, trying to raise consciousness about apartheid in our community, and fearing Mandela would stay in jail for the rest of his life.

But then, something amazing happened: In 1990, after 27 years in prison, Mandela was actually free.

His long walk to freedom brought him on a multicity U.S. tour, which concluded in June at the Los Angeles Coliseum, where my dad took our family to see him. It was a warm summer night. Music entertained the 70,000 people waiting to hear word from a freed political prisoner from a land nearly 10,000 miles away. Bill Cosby was on the stage. Jesse Jackson warmed up the throngs.

And then, finally, the man of the hour addressed the crowd. According to the Los Angeles Times, "Mandela thanked Los Angeles for its 'staunch' financial and political support in the crusade to end South Africa's apartheid system," which seems like a shout-out to both the celebrities and grassroots organizers like my dad for their help. I don't remember the exact content of the speech, but I do remember the feeling in my heart in watching my dad's face light up as Mandela came out, as my father clapped his large hands, and took off his hat, and rose to his feet.

The look on my dad's face was the opposite of what I'd seen in it when he was stopped by the cops.

It was a look of ebullient joy, of validation of what was possible.

It was the look of a historian getting to see history, of an activist seeing justice, of the grandson of a slave looking at freedom incarnate.

My dad wouldn't ever get to travel to Africa as I have, or live long enough to know of Barack Obama as a senator, let alone as president. The vast majority of my dad's time expended as an activist was on causes that did not have much immediate success.

But, on that one night in the summer of 1990, when Nelson Mandela addressed Los Angeles and thanked the crowd — including my father — for its support, I got to see my dad content in witnessing the arc of the moral universe bend decidedly toward justice. For once, he got to see it with his own eyes.

My dad bought me a T-shirt from the rally with a picture of Mandela on it, and I wore it proudly to school the following Monday. A classmate ratted me out as a "terrorist" and yelled that I was "supporting a terrorist!" Bart Simpson T-shirts had been recently banned at my junior high school, and my classmate tried to report that I was wearing inappropriate clothing. He told a teacher that I was wearing the shirt of someone who "wants to kill all the white people!"

He couldn't have been farther from the truth. Mandela would establish the Truth and Reconciliation Commission, setting the standard for the non-retaliatory model of justice after conflict. He would oversee the world's first constitution to include gay and lesbian rights. He would guide the Republic of South Africa in its infant days. In his remaining 23 years of life, Mandela would inspire the world to conceive of freedom and peace in ways it had not since Martin Luther King Jr. and Mohandas Ghandi walked the earth.

But I will always be grateful for a very small, very personal gift from Mandela: the look he put on my father's face at the Los Angeles Coliseum, which I will remember for all of my days.